Using Roman (Latin) characters to express the sound of Chinese words is a helpful tool in learning the language. There are several basic systems in current use within the United States.

Pinyin: Pinyin (meaning "spell-sound") was compiled in 1958 and is now the most recognized and popular method of romanization. The Pinyin system is the romanization of the Zhu Yin system of pronounciation commonly called "bo-po-mo-fo" that was a phonetic tool used by young children. Pinyin became a United Nations standard in 1977 and an International Standard Organization (ISO) standard in 1982. It is the exclusive system of international media outlets and recently adopted by the U.S. Library of Congress.

Wade-Giles: Officially published in 1959 by Thomas Francis Wade. Developed from R. Morrison's 1815 romanization system, then later modified by Allen Giles in 1912. It was very popular in English-speaking countries and remains the preferred system in many countries for expressing personal names.

Yale: Created in 1948 for teaching American military personnel the Chinese language. It then spread through the U.S. and became popular in Taiwan as a method of teaching Chinese to foreigners.

Chinese Post Office: While not an officially recognized romanization system, this was an old system used to express place-names. Usually used in combination with Wade-Giles for non-place names. Examples are Peking, Tsingtao, and Chungking. These spellings are still common in English-speaking countries.

Zu Yin: A system used by Chinese speaking children to learn Chinese phonetics. Sometimes referred to as the "bo-po-mo-fo" method, it uses non-latin characters to represent the various phonetics. This is a useful system for teaching Mandarin to students who speak other Chinese dialetics or Asian languages.